1. Field of the Invention
The present invention relates to a multi-plate type image pick-up apparatus provided with a plurality of imagers.
2. Description of the Related Art
Conventionally, imagers (image pick-up tubes and solid state imagers) have been widely used for image pick-up apparatuses. In particular, in regard to a color imager mounted on a color image pick-up apparatus of a single pipe type or a single-plate type (Single Sensor), a color image pick-up unit can be configured with one imager; therefore, since a color separation prism is not needed, the lens can be miniaturized. Such a type of color imager has many characters as follows: The adjustment of the position of each imager or the like, which would need to be performed for multi-plate type imagers, does not need to be performed; Since only one imager is needed, the power consumption is small; and so on. The color imagers greatly contribute to the miniaturization of color image pick-up apparatuses and to power saving. In particular, a single-plate type color camera in which a color CCD (Charge Coupled Device) imager is used is a mainstream image pick-up apparatus.
Since all of the aforementioned color imagers obtain color information on one light receiving surface, they modulate a color within the light receiving surface by using a color filter called a stripe filter, a mosaic filter, or the like. In other words, the color imagers have, for example, a structure in which a color filter of one of RGB colors is put on each photoelectric transducer (each pixel) in a predetermined regular arrangement; accordingly, each pixel has a different spectral responsivity.
An image signal obtained via a color imager picking up the image of a subject includes dot-sequential color information which depends on the arrangement of color filters. Accordingly, in accordance with the arrangement of the color filters, the obtained image signal is separated into signals each corresponding to the color of a color filter. By extracting the separated signals, color information can be extracted; therefore, color image pick-up can be performed using one imager.
As an example, in regard to multi-plate type color image pick-up apparatuses, the following apparatuses are proposed. Japanese Laid-open Patent Publication No. 62-104294 proposes a multi-plate type image pick-up apparatus which achieves a high sensitivity and a high resolution. Japanese Laid-open Patent Publication No. 5-76015 proposes a two-plate type image pick-up apparatus which reduces color moire and achieves a high resolution. Japanese Laid-open Patent Publication No. 8-79597 proposes a multi-plate type image pick-up apparatus which can pick up the image of a subject and detect the state of incident light at the same time.